In modern technology it is frequently necessary to transport and store radioactive materials, such as radioactive wastes, in small units, such that the radioactivity in these materials does not escape into the environment.
The canisters, containers, receptacles or enclosures used for this purpose should generally be of a sort which enables them to be transported or moved around and the receptacles must be of a material capable of absorbing radioactivity in particular of acting as a neutron absorber.
Various receptacles and receptacle configurations have been provided for this purpose and can be used particularly for the shielding storage and transport of radioactive waste, such as spent nuclear fuel elements, nuclear fuel residues and the products of nuclear fuel reclaiming plants. It is known, for example, to provide a transport or storage receptacle for radioactive waste, especially nuclear reactor fuel elements, which comprises a receptacle shell, a receptacle bottom and a cover for the chamber surrounded by the shell and closed at its face by the bottom.
More specifically, in this earlier system, the receptacle shell and receptacle bottom is cast in one piece (unitarily) from metal especially cast iron or cast steel, the cast iron being generally spherolytic cast iron. Such substances have a high neutron absorption cross section.
The cover can be a shielding cover, i.e. can have a portion which is recessed in the wall of the receptacle so that any gaps between the cover and the wall are labyrinthine in configuration, thereby, precluding a straight-line path for the escape of radiation.
Naturally, the thickness of our receptacle wall or shell, of the bottom and of the shielding cover, measured perpendicular to the surface defining the storage compartment or chamber for the radioactive waste must be sufficient enable the receptacle to withstand the static or dynamic stress to which the receptacle may be subject during transport or storages and, in addition, must be sufficient to prevent any escape of the radiation to the exterior whether the radiation is gamma rays or neutron emissions.
In conventional systems of the above described type, servicing of the receptacles is a problem since access parts and fittings are provided on various sides of the receptacles so that operations which must be carried out necessitate manipulating the vessel.
Furthermore, it is frequently desirable to provide such receptacles in conjunction with apparatus for the processing of radioactive waste or other materials. The apparatus can be of various types and connection of the receptacle to such apparatusses must be afforded (see German Patent Application-Offenlegungsschriften-DT-OS Nos. 25 11 957 and 25 20 850. With such systems, the conventional receptacles cause problems because of the complex connections which may be necessary.